DESCRIPTION: (Adapted from the application) Changes in the rate or efficiency of proteolysis have been implicated as potentially important factors in the mechanism of aging. One of the pathophysiological abnormalities associated with aging and age-related neurodegenerative disorders might be abnormal regulation of intracellular calcium homeostasis, which can lead to excessive activation of calcium-dependent enzymes, such as calpains, as seen in Alzheimer s disease. Calcium-mediated injury is considered as one potentially important contributing mechanism in neurodegeneration. This application is based on the hypothesis that abnormalities in the regulation of calcium-activated neutral proteinase (calpain) represent important pathophysiological mechanisms in etiopathogenesis of neurodegeneration and aging. The broad, long-term objectives of this proposal are to provide the educational, environmental, and technical resources necessary for the candidate to become an independent researcher. In the educational part of the proposal, the candidate will gain further knowledge of molecular biology, advanced neurobiology, mathematical modeling and statistical analysis. In the scientific part of the proposal, the candidate will apply the knowledge to answering specific questions of the pathogenesis of neurodegeneration and aging. Specific aim 1 will determine which factors regulate the recovery of neurons from calcium load, using single cell digital imaging of cell calcium. Specific aim 2 will determine if chronic decrease in the cellular concentration of calpastation will affect the vulnerability of cells to calcium-mediated injury, using antisense oligodeoxynucleotides to generate gradual and prolonged depletion of calpastatin. In specific aim 3 the candidate will establish neuronal cultures with downregulated or upregulated calpain/calpastatin system using genetic engineering and determine the pathophysiological consequences of the manipulation. Specific aim 4 will test if combinational therapy with calpain inhibitors together with other putative neuroprotective agents provides higher level of neuroprotection as compared to calpain inhibitors alone. Successful completion of the proposed experiments will provide new insight into fundamental mechanisms of neurodegeneration. The results might suggest new avenues and approaches for the prevention and treatment of neuronal death in age-related neurodegenerative disorders and stroke. Successful completion of the proposal will give the candidate firm foundation in neuropharmacology, molecular biology, cellular physiology, and computational neuroscience to become a successful and independent researcher in cellular biology of neuronal degeneration.